This invention relates generally to semiconductor components, and relates more particularly to electrical isolation of semiconductor devices.
Automotive and other high power applications make use of various types of semiconductor components, including discrete devices and integrated circuits. As an example, the discrete devices can be power Metal-Oxide-Semiconductor (MOS) transistors having source, gate, and drain terminals. In order to reduce the cost and space required for the semiconductor components, MOS transistors and other semiconductor devices have been combined onto a single semiconductor chip. The combination of various semiconductor devices onto a single chip, however, can lead to the significant problem of minority carrier injection, which occurs when the drain terminal of the power MOS transistor is forward biased. More specifically, the forward biasing of the MOS drain terminal injects minority carriers into the semiconductor substrate, and the minority carriers can degrade the performance of the integrated circuit or circuits located on the same semiconductor chip.
Several attempts have been made to either contain the injected minority carriers or suppress the injection of minority carriers. These attempts, however, suffer from the disadvantages of significant silicon area consumption, low drain-to-source breakdown voltage, large epitaxial semiconductor layer thickness, and/or non-isolated power transistors. Accordingly, a need exists for a semiconductor component wherein a power transistor is combined with an integrated circuit on a single semiconductor chip, where the power transistor has a high drain-to-source breakdown voltage and is isolated from the integrated circuit, and where the significant silicon area consumption required by existing isolation techniques is avoided.